Hammer assembly



' HAMMER ASSEMBLY Filed Jan. 24, 1938 c. F. SCHUTTE ET AL 2,133,212

Patented Oct. 11, 1938 UNITED STATES PATENT OFFICE HAMMER ASSEMBLYCharles F. Schutte and Herman D'. Schutte, Snyder, N. Y., assignors ofone-fourth to Nellie D. Schutte, Snyder, N. Y.

Application January 24, 1938, Serial No. 186,719

4 Claims.

This invention relates to hammer assemblies for hammer mills of the typein which the hammers are detachably connected to the outer ends of swingarms pivoted to a driven rotary member,

each hammer being so constructed as to provide a plurality of impactfaces so that when one impact face of a hammer becomes worn the hammermay be repositioned on its swing arm to present a new impact face. Sucha type of hammer is disclosed in Patent No. 1,821,482 of Charles F.Schutte, dated September 1, 1931, upon which the hammer assembly of thepresent invention represents an improvement.

While hammers of the renewable face type have been successfully employedin hammer mills, difiiculty is encountered in providing simple andeffective means for non-rotatably attaching the hammers to the swingarms so as to withstand the repeated shocks to which they are subjectedand to permit their quick disengagement from the swing arms when itbecomes necessary to change the impact faces of the hammers.

It is an important object of our invention to provide a quicklyreleasable connection for attaching the hammers to their swing armswhich is composed of a minimum number of parts and so arranged as to beprotected against flying lumps of material in the crushing chamber ofthe mill. An advantageous feature of the invention is the adaptabilityof the connecting means to different types of hammer assemblies in whicheither a single hammer or a plurality of hammers arranged in parallel iscarried at the outer end of a swing arm or between a pair of Swing armspivoted to the rotary member.

Another object of our invention is to provide connecting means for thehammers which project only a small distance beyond the lateral surfacesof the hammers or the swing arms so as to permit the swing arms to beassembled in closely spaced relation on the rotary member.

Other objects and advantages will be apparent from the followingdetailed description of several preferred embodiments of the invention,reference being had to the annexed drawing, in which:

Figure 1 is a side view of a hammer assembly of the type in which a pairof'hammers are mounted on the end of a swing arm;

Figure 2 is a longitudinal cross-sectional view of the hammer assemblyof Fig. 1 viewed at right angles thereto;

Figure 3 illustrates the various parts of the hammer connection;

Figure 4 is a plan view of a difierent type of hammer assembly in whicha single hammer is supported between a pair of swing arms; and

Figure 5 is a plan view of a hammer assembly similarto that of Fig. 4but in which a series of hammers separated by spacing members are sup--ported between the swing arms.

In the type of hammer assembly shown in Figs. 1 and 2 incorporating theinvention, a pair of hammers l is carried upon the end of a swing arm 2which latter is pivoted by means of a pin 3 to a driven rotary member 4.The hammers are each provided with four equidistantly spaced, radiallyextending legs la. providing a corresponding number of impact faces lb.In accordance with the usual mode of hammer mill operation, when therotary member 4 is operated, centrifugal force throws the swing arm 2outwardly and causes the hammers to impart blows with crushing force to:the material contained within the crushing chamber of the mill, not

shown.

In order to permit the repositioning of the hammers upon theswing armsso as to bring a new impact face of a hammer into operative positionafter one of the faces has become worn, it is usual to provide adetachable connection for nonrotatively retaining the hammers inassembly with their swing arm. According to the present invention thereis provided a connection which may take the form of that bestillustrated in Fig. 3 and comprising a pin 5 of square transversecross-section and having an axial internally threaded bore 6 extendingthroughout its length, a pair of screws 1 having enlarged clamp ingheads la and collars 8 adapted to encircle the screws and providecountersunk seats 9 for the screw heads.

As best shown in the cross-sectional view of Fig. 2, the swing arm 2 andthe pair of hammers I located upon opposite sides of the arm areprovided with registering square shaped openings of a size justsuflicient to pass the square pin 5. The pin is of a length so as toterminate approximately flush with the flat outer faces of the hammers.The collars are slipped over the shanks of the screws and the screwsthen threaded into the bore of the pin, as by means of a screw driverengaging kerfs 10 in the heads of the screws, until their headstightlyengage the bottoms of the seats 9. This causes the collars 8 tobe drawn into clamping engagement with the hammers and prevents endwisedisplacement of the pins in their openings.

When so assembled with the swing arm the hammers are positivelyrestrained against rotation by means of the square pin engagingcomplementary openings in the hammers and swing arm. At the same time itis only necessary when one impact face of a hammer becomes worn toremove the screw 7 which holds the hammer in association with the swingarm, together with its collar 8, slip the hammer from the end of pin 5,

turn the hammer through 45 degrees to bring a new impact face tooperative position and then reclamp the hammer on the swing arm in itsnew position. Likewise the hammers may be entirely reversed in positionas occasion demands so as to make available four additional edges oftheir impact faces, each hammer thereby furnishing eight grindingpositions upon their four impact faces.

In Fig. 4 is shown another form that the invention may assume. In thehammer assembly of this figure a single hammer 20 of the multiple facetype is located between and at the outer ends of a pair of companionswing arms 2|. The hammer is non-rotatably and detachably secured to theswing arms by a connection corresponding to that disclosed in Fig. 3.This assembly differs in no essential respect from that previouslydescribed except that a square pin 22, corresponding to pin of theassembly of Figs. 1 and 2, extends through aligned openings in the twoswing arms and hammer. The pin is retained in association with the swingarms by screws 23 encircled by collars 24, corresponding to the screws 1and collars 8 of the aforementioned figures. The screws are threadedinto opposite ends of a central bore 25 in the pin and their enlargedheads seat within counter-sinks in the collars, as indicated in dottedlines, so as to retain the pin against endwise movement.

Another embodiment of the invention is shown in Fig. 5 which discloses ahammer assembly which partakes of the nature of both of the hammerassemblies previously described. This assembly comprises a pair of swingarms 30 (although any suitable number of swing arms may be provided atspaced intervals) between which arms are assembled a series of hammers3| of the multiple face type. A square pin 32 passes throughcorresponding openings in the swing arms and hammers and its endsproject a sufficient distance beyond the outwardly disposed sides of thepair of swing arms to allow additional hammers 3Ia to be fittedthereover. Headed screws 33 encircled by collars 34 (corresponding tothe screws 1 and collars 8 of the embodiment of Figs. 1 and 2) areaxially threaded into a central bore in the pin and clamp the collarsagainst the sides of the hammers 3la. For uniformly spacing apart theseries of hammers located between the pair of swing arms, spacer rings35 centrally provided with square openings passing the pin 32 arepositioned between adjacent hammers.

It will be apparent from the embodiments of the invention describedabove that the hammers are positively locked against rotation upon theends of the swing arms and that in every instance the square pins areenclosed throughout their length and protected from flying debris withinthe mill. This prevents the pins from damage and avoids chipping anddistortion of the corners of the square pin which would interfere withthe ready removal of the pins from the hammers when changing theirimpact faces.

The transverse cross-sectional shape of the pin need not necessarily besquare but may be of other non-circular shapes. This would beparticularly true in the case of hammers having a different number ofimpact faces from the four faces disclosed in the hammers of the aboveembodiments. However, in the case of square or rectangular pins, thefour right-angled corners have been found to afford maximum resistanceagainst turning of the hammers thereon as well as to permit their readyassembly with the hammers.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics of the invention, and thepresent embodiments are therefore to be considered as illustrative andnot restrictive, and all changes which come within the meaning and rangeof equivalency of the claims are therefore intended to be embracedtherein.

We claim:

1. A hammer assembly of the class described comprising a swing arm andmeans for nonrotatably and detachably connecting a hammer having aplurality of impact faces to the outer end of the swing arm, saidconnecting means comprising a pin of angular transverse cross-sectionextending through registering openings corresponding to thecross-section of the pin in the swing arm and hammer, means forpreventing endwise displacement of the pin in one direction and meansfor preventing endwise displacement of the pin in the oppositedirection, said lastmentioned means comprising a screw axially threadedinto the pin and having an enlarged clamping head and a collarsurrounding said head and providing a countersunk seat for receiving theclamping head of said screw.

2. A hammer assembly of the class described comprising a swing arm andmeans for nonrotatably and detachably connecting a hammer having aplurality of impact faces to the outer end of the swing arm, saidconnecting means comprising a pin of square transverse cross-sectionextending through registering openings corresponding to thecross-section of the pin in the swing arm and hammer and meanspreventing endwise displacement of the pin, said last-mentioned meanscomprising screws axially threaded into opposite ends of the pins andhaving enlarged clamping heads and collars surrounding the screws andproviding countersunk seats for receiving the clamping heads of saidscrews, whereby the pin is protected substantially throughout its entiresurface against damage.

3. A hammer assembly of the class described comprising a plurality ofswing arms arranged in parallel and means for non-rotatably anddetachably connecting a series of hammers each having a plurality ofimpact faces to the outer ends of said swing arms, said connecting meanscomprising a pin of angular transverse crosssection extending throughregistering openings corresponding to the cross-section of the pin inthe swing arms and hammers, spacer members surrounding the pin anddisposed between adjacent hammers and means preventing endwisedisplacement of the pin, said last-mentioned means comprising screwsaxially threaded into opposite ends of the pins and having enlargedclamping heads and collars surrounding the screws and providingcountersunk seats for receiving the clamping heads of said screws,whereby the pin is protected substantially throughout its entire surfaceagainst damage.

4. A hammer assembly of the class described comprising a swing arm andmeans for nonrotatably and detachably connecting a hammer having aplurality of impact faces to the outer end of the swing arm, saidconnecting means comprising a pin of angular transverse cross-sectionextending through registering openings corresponding to thecross-section of the pin in the swing arm and hammer, means forpreventing endwise displacement of the pin in one direction and meansfor preventing endwise displacement of the pin in the oppositedirection, said last-mentioned means comprising a screw axially threadedinto the pin and having an enlarged clamping head and a collarsurrounding said head and providing a countersunk seat for receiving theclamping head of said screw, said collar being of greater diameterthanthe maximum transverse dimension of the pin so as to completely cover anend of the pin.

CHARLES F. SCHUTTE.

HERMAN D. SCHUTTE.

